BMC Clinical Pharmacology最新文献

Background: Panitumumab is a fully human antibody against the epidermal growth factor receptor that is indicated for the treatment of metastatic colorectal cancer (mCRC) after disease progression on standard chemotherapy. The purpose of this analysis was to examine the immunogenicity of panitumumab and to evaluate the effect of anti-panitumumab antibodies on pharmacokinetic and safety profiles in patients with mCRC receiving panitumumab in combination with oxaliplatin- or irinotecan-based chemotherapies.

Methods: Three validated assays (two screening immunoassays and a neutralizing antibody bioassay) were used to detect the presence of anti-panitumumab antibodies in serum samples collected from patients enrolled in four panitumumab combination chemotherapy clinical trials. The impact of anti-panitumumab antibodies on pharmacokinetic and safety profiles was analyzed using population pharmacokinetic analysis and descriptive statistics, respectively.

Results: Of 1124 patients treated with panitumumab in combination with oxaliplatin- or irinotecan-based chemotherapy with postbaseline samples available for testing, 20 (1.8%) patients developed binding antibodies and 2 (0.2%) developed neutralizing antibodies. The incidence of anti-panitumumab antibodies was similar in patients with tumors expressing wild-type or mutant KRAS and in patients receiving oxaliplatin- or irinotecan-based chemotherapies. No evidence of an altered pharmacokinetic or safety profile was found in patients who tested positive for anti-panitumumab antibodies.

Conclusions: The immunogenicity of panitumumab in the combination chemotherapy setting was infrequent and similar to the immunogenicity observed in the monotherapy setting. Panitumumab immunogenicity did not appear to alter pharmacokinetic or safety profiles. This low rate of immunogenicity may be attributed to the fully human nature of panitumumab.

Background: According to the World Health Organization (WHO) the cost of adverse drug reactions (ADRs) in the general population is high and under-reporting by health professionals is a well-recognized problem. Another way to increase ADR reporting is to let the consumers themselves report directly to the authorities. In Sweden it is mandatory for prescribers to report serious ADRs to the Medical Products Agency (MPA), but there are no such regulations for consumers. The non-profit and independent organization Consumer Association for Medicines and Health, KILEN has launched the possibility for consumers to report their perceptions and experiences from their use of medicines in order to strengthen consumer rights within the health care sector. This study aimed to analyze these consumer reports.

Methods: All reports submitted from January 2002 to April 2009 to an open web site in Sweden where anyone could report their experience with the use of pharmaceuticals were analyzed with focus on common psychiatric side effects related to antidepressant usage. More than one ADR for a specific drug could be reported.

Results: In total 665 reports were made during the period. 442 reports concerned antidepressant medications and the individual antidepressant reports represented 2392 ADRs and 878 (37%) of these were psychiatric ADRs. 75% of the individual reports concerned serotonin-reuptake inhibitor (SSRI) and the rest serotonin-norepinephrine reuptake inhibitor (SNRI). Women reported more antidepressant psychiatric ADRs (71%) compared to men (24%). More potentially serious psychiatric ADRs were frequently reported to KILEN and withdrawal symptoms during discontinuation were also reported as a common issue.

Conclusions: The present study indicates that consumer reports may contribute with important information regarding more serious psychiatric ADRs following antidepressant treatment. Consumer reporting may be considered a complement to traditional ADR reporting.

Background: Tobacco smoking remains the leading modifiable health hazard and varenicline is amongst the most popular pharmacological options for smoking cessation. The purpose of this study is to critically evaluate the extent of gastrointestinal adverse effects of varenicline when used at maintenance dose (1 mg twice a day) for smoking cessation.

Methods: We conducted a meta-analysis of randomised controlled trials published in PUBMED and EMBASE according to the PRISMA guidelines. Selected studies satisfied the following criteria: (i) duration of at least 6 weeks, (ii) titrated dose of varenicline for 7 days then a maintenance dose of 1 mg twice-per-day, (iii) randomized placebo-controlled design, (iv) extractable data on adverse event - nausea, constipation or flatulence. Data was synthesized into pooled odd ratios (OR) basing on random effects model. Quality of studies was also rated as per Cochrane risk-of-bias assessment. Number need to harm (NNH) was calculated for each adverse effect.

Results: 98 potentially relevant studies were identified, 12 of which met the final inclusion criteria (n = 5114). All 12 studies reported adverse events on nausea, which led to an OR of 4.45 (95% CI = 3.79-5.23, p < 0.001; I(2) = 0.06%, CI = 0%-58.34%) and a NNH of 5. Eight studies (n = 3539) contain data on constipation pooled into an OR of 2.45 (95% CI = 1.61-3.72, p < 0.001; I(2) = 34.09%, CI = 0%-70.81%) with a NNH of 24. Finally, five studies (n = 2516) reported adverse events of flatulence, which pooled an OR of 1.74 (95% CI = 1.23-2.48, p = 0.002; I(2) = 0%, CI = 0%- 79.2%) with a NNH of 35.

Conclusions: Use of varenicline at maintenance dose of 1 mg twice a day for longer than 6 weeks is associated with adverse gastrointestinal effects. In realistic terms, for every 5 treated subjects, there will be an event of nausea, and for every 24 and 35 treated subjects, we will expect an event of constipation and flatulence respectively. Family physicians should counsel patients of such risks accordingly during their maintenance therapy with varenicline.

Background: Spontaneous reporting of adverse drug reactions (ADRs) is an important method for pharmacovigilance, but under-reporting and poor quality of reports are major limitations. The aim of this study was to evaluate if repeated one-page ADR information letters affect (i) the reporting rate of ADRs and (ii) the quality of the ADR reports.

Methods: All 151 primary healthcare units in the Region Västra Götaland, Sweden, were randomly allocated (1:1) to an intervention (n = 77) or a control group (n = 74). The intervention consisted of one-page ADR information letters administered at three occasions during 2008 to all physicians and nurses in the intervention units. The number of ADR reports received from the 151 units was registered, as was the quality of the reports, which was defined as high if the ADR was to be reported according to Swedish regulations, that is, if the ADR was (i) serious, (ii) unexpected, and/or (iii) related to the use of new drugs and not labelled as common in the Summary of Product Characteristics. A questionnaire was administered to evaluate if the ADR information letter had reached the intended recipient.

Results: Before the intervention, no significant differences in reporting rate or number of high quality reports could be detected between the randomization groups. In 2008, 79 reports were sent from 37 intervention units and 52 reports from 30 control units (mean number of reports per unit ± standard deviation: 1.0 ± 2.5 vs. 0.7 ± 1.2, P = 0.34). The number of high quality reports was higher in intervention units than in control units (37 vs. 15 reports, 0.5 ± 0.9 vs. 0.2 ± 0.6, P = 0.048). According to the returned questionnaires (n = 1,292, response rate 57%), more persons in the intervention than in the control group had received (29% vs. 19%, P < 0.0001) and read (31% vs. 26%, P < 0.0001) an ADR information letter.

Conclusions: This study suggests that repeated ADR information letters to physicians and nurses do not increase the ADR reporting rate, but may increase the number of high quality reports.

Background: In many but not in all neuropsychological studies buprenorphine-treated opioid-dependent patients have shown fewer cognitive deficits than patients treated with methadone. In order to examine if hypothesized cognitive advantage of buprenorphine in relation to methadone is seen in clinical patients we did a neuropsychological follow-up study in unselected sample of buprenorphine- vs. methadone-treated patients.

Methods: In part I of the study fourteen buprenorphine-treated and 12 methadone-treated patients were tested by cognitive tests within two months (T1), 6-9 months (T2), and 12-17 months (T3) from the start of opioid substitution treatment. Fourteen healthy controls were examined at similar intervals. Benzodiazepine and other psychoactive comedications were common among the patients. Test results were analyzed with repeated measures analysis of variance and planned contrasts. In part II of the study the patient sample was extended to include 36 patients at T2 and T3. Correlations between cognitive functioning and medication, substance abuse, or demographic variables were then analyzed.

Results: In part I methadone patients were inferior to healthy controls tests in all tests measuring attention, working memory, or verbal memory. Buprenorphine patients were inferior to healthy controls in the first working memory task, the Paced Auditory Serial Addition Task and verbal memory. In the second working memory task, the Letter-Number Sequencing, their performance improved between T2 and T3. In part II only group membership (buprenorphine vs. methadone) correlated significantly with attention performance and improvement in the Letter-Number Sequencing. High frequency of substance abuse in the past month was associated with poor performance in the Letter-Number Sequencing.

Conclusions: The results underline the differences between non-randomized and randomized studies comparing cognitive performance in opioid substitution treated patients (fewer deficits in buprenorphine patients vs. no difference between buprenorphine and methadone patients, respectively). Possible reasons for this are discussed.

Background: The effect of statin therapy on mortality in critically ill patients is controversial, with some studies suggesting a benefit and others suggesting no benefit or even potential harm. The objective of this study was to evaluate the association between statin therapy during intensive care unit (ICU) admission and all-cause mortality in critically ill patients.

Methods: This was a nested cohort study within two randomised controlled trials conducted in a tertiary care ICU. All 763 patients who participated in the two trials were included in this study. Of these, 107 patients (14%) received statins during their ICU stay. The primary endpoint was all-cause ICU and hospital mortality. Secondary endpoints included the development of sepsis and severe sepsis during the ICU stay, the ICU length of stay, the hospital length of stay, and the duration of mechanical ventilation. Multivariate logistic regression was used to adjust for clinically and statistically relevant variables.

Results: Statin therapy was associated with a reduction in hospital mortality (adjusted odds ratio [aOR] = 0.60, 95% confidence interval [CI] 0.36-0.99). Statin therapy was associated with lower hospital mortality in the following groups: patients >58 years of age (aOR = 0.58, 95% CI 0.35-0.97), those with an acute physiology and chronic health evaluation (APACHE II) score >22 (aOR = 0.54, 95% CI 0.31-0.96), diabetic patients (aOR = 0.52, 95% CI 0.30-0.90), patients on vasopressor therapy (aOR = 0.53, 95% CI 0.29-0.97), those admitted with severe sepsis (aOR = 0.22, 95% CI 0.07-0.66), patients with creatinine ≤ 100 μmol/L (aOR = 0.14, 95% CI 0.04-0.51), and patients with GCS ≤ 9 (aOR = 0.34, 95% CI 0.17-0.71). When stratified by statin dose, the mortality reduction was mainly observed with statin equipotent doses ≥ 40 mg of simvastatin (aOR = 0.53, 95% CI 0.28-1.00). Mortality reduction was observed with simvastatin (aOR = 0.37, 95% CI 0.17-0.81) but not with atorvastatin (aOR = 0.80, 95% CI 0.84-1.46). Statin therapy was not associated with a difference in any of the secondary outcomes.

Conclusion: Statin therapy during ICU stay was associated with a reduction in all-cause hospital mortality. This association was especially noted in high-risk subgroups. This potential benefit needs to be validated in a randomised, controlled trial.

Background: The study aimed to investigate the pharmacokinetics of intravenous ciprofloxacin and the adequacy of 400 mg every 12 hours in critically ill Intensive Care Unit (ICU) patients on continuous veno-venous haemodiafiltration (CVVHDF) with particular reference to the effect of achieved flow rates on drug clearance.

Methods: This was an open prospective study conducted in the intensive care unit and research unit of a university teaching hospital. The study population was seven critically ill patients with sepsis requiring CVVHDF. Blood and ultrafiltrate samples were collected and assayed for ciprofloxacin by High Performance Liquid Chromatography (HPLC) to calculate the model independent pharmacokinetic parameters; total body clearance (TBC), half-life (t1/2) and volume of distribution (Vd). CVVHDF was performed at prescribed dialysate rates of 1 or 2 L/hr and ultrafiltration rate of 2 L/hr. The blood flow rate was 200 ml/min, achieved using a Gambro blood pump and Hospal AN69HF haemofilter.

Results: Seventeen profiles were obtained. CVVHDF resulted in a median ciprofloxacin t1/2 of 13.8 (range 5.15-39.4) hr, median TBC of 9.90 (range 3.10-13.2) L/hr, a median Vdss of 125 (range 79.5-554) L, a CVVHDF clearance of 2.47+/-0.29 L/hr and a clearance of creatinine (Clcr) of 2.66+/-0.25 L/hr. Thus CVVHDF, at an average flow rate of ~3.5 L/hr, was responsible for removing 26% of ciprofloxacin cleared. At the dose rate of 400 mg every 12 hr, the median estimated Cpmax/MIC and AUC0-24/MIC ratios were 10.3 and 161 respectively (for a MIC of 0.5 mg/L) and exceed the proposed criteria of >10 for Cpmax/MIC and > 100 for AUC0-24/MIC. There was a suggestion towards increased ciprofloxacin clearance by CVVHDF with increasing effluent flow rate.

Conclusions: Given the growing microbial resistance to ciprofloxacin our results suggest that a dose rate of 400 mg every 12 hr, may be necessary to achieve the desired pharmacokinetic-pharmacodynamic (PK-PD) goals in patients on CVVHDF, however an extended interval may be required if there is concomitant hepatic impairment. A correlation between ciprofloxacin clearance due to CVVHDF and creatinine clearance by the filter was observed (r2 = 0.76), providing a useful clinical surrogate marker for ciprofloxacin clearance within the range studied.

Trial registration: Current Controlled Trials ISRCTN52722850.

Background: The lipid fraction of cell membranes consists of polyunsaturated fatty acids (PUFAS), and chronic alcohol use alters it, modifying its permeability, what might contribute for the dysfunctional metabolism observed in the central nervous system of alcohol dependent patients. Therefore, the supplementation of PUFAS can be an important adjuvant in alcoholism treatment.

Methods: This was a placebo controlled, double blind, randomized study where, 80 alcohol dependent patients, according to DSM-IV, were allocated in four groups with 20 patient each: 'PUFAS', 'Naltrexone', 'Naltrexone + PUFAS' and 'Placebo'. Those substances were administered for 90 days and scales were applied to assess patients craving (OCDS) and alcohol dependence severity (SADD) at baseline and after 90 days. PUFAS serum levels were assessed before and after treatment by high performance liquid chromatography assay.

Results: Forty-three patients completed the trial. There was a significant improvement over time on drinking days, SADD and OCDS scores in all groups (p < 0.001). The drinking days comparison between groups did not show statistical significant difference. The same effect was observed for compulsion (OCDS) and severity of dependence scale (SADD). The serum levels of PUFAS increased in all the supplemented groups after treatment, although not significantly.

Conclusions: The oral supplementation of 2 g PUFAS for 3 months did not significantly differ from placebo in reducing the amount of alcohol ingestion, or OCDS and SADD scores in a group of alcohol dependent patient.

Trial registration: NCT01211769.

Background: One of the most critical problems about antimicrobial therapy is the increasing resistance to antibiotics. Previous studies have shown that there is a direct relation between erroneous prescription, dosage, route, duration of the therapy and the antibiotics resistance. Other important point is the uncertainty about the quality of the prescribed medicines. Some physicians believe that generic drugs are not as effective as innovator ones, so it is very important to have evidence that shows that all commercialized drugs are suitable for therapeutic use.

Methods: Microbial assays were used to establish the potency, the Minimal Inhibitory Concentrations (MICs), the Minimal Bactericidal Concentration (MBCs), the critical concentrations, and the production of spontaneous mutants that are resistant to vancomycin.

Results: The microbial assay was validated in order to determine the Vancomycin potency of the tasted samples. All the products showed that have potency values between 90 - 115% (USP requirement). The products behave similarly because the MICs, The MBCs, the critical concentrations, the critical concentrations ratios between standard and samples, and the production of spontaneous mutants don't have significant differences.

Conclusions: All products analyzed by microbiological tests, show that both trademarks and generics do not have statistical variability and the answer of antimicrobial activity Show also that they are pharmaceutical equivalents.

Background: Ibuprofen treatment of patent ductus arteriosus (PDA) has been shown to be as effective as indomethacin in small randomized controlled trials, with possibly fewer adverse effects. However, adverse renal effects of ibuprofen have been noted in some trials and suspected in our practice.The purpose of this study was to examine whether ibuprofen and indomethacin treatment of PDA have comparable effects on renal function as evidenced by urine output and serum creatinine.

Methods: Retrospective chart review of 350 patients. Serum creatinine and urine output were recorded prior to start of treatment, during each course and after the last course of treatment. Pre-treatment mean creatinine and urine output values were compared to treatment and post treatment means using 2-factor repeated measures ANOVA.

Results: 165 patients were treated with indomethacin (2005-2006) and 185 received ibuprofen (2007-2008). There was no difference between treatment groups in demographics or baseline renal function. For both groups, the number of treatment courses was inversely correlated with birth weight and gestational age. Analysis of the first course including all patients, revealed significant increase in creatinine and decrease in urine output with both drugs, with a more pronounced effect of indomethacin on creatinine. In the subgroup of 219 patients who received only one treatment course, there was a significant increase in creatinine after indomethacin, but not after ibuprofen. In the 131 who received 2 or more courses, the decrease in urine output and increase in creatinine were not different between drugs. There were significant decreases in urine output observed in the second and third courses of ibuprofen treatment (both by 0.9 mL/kg/hr).

Conclusion: Both drugs have a similar short-term effect on renal function. Indomethacin had a more prominent initial effect, while ibuprofen decreased renal function during the second and third courses similarly to indomethacin. The changes in renal function seen with ibuprofen treatment should be considered in fluid and electrolyte management, especially if treatment beyond one course is required.